pubsubclient/PubSubClient/PubSubClient.cpp
2012-01-25 14:36:16 +01:00

238 lines
6.0 KiB
C++

/*
PubSubClient.cpp - A simple client for MQTT.
Nicholas O'Leary
http://knolleary.net
*/
#include "PubSubClient.h"
#include <EthernetClient.h>
#include <string.h>
PubSubClient::PubSubClient() : _client() {
}
PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, void (*callback)(char*,uint8_t*,int)) : _client() {
this->callback = callback;
this->ip = ip;
this->port = port;
}
PubSubClient::PubSubClient(String domain, uint16_t port, void (*callback)(char*,uint8_t*,int)) : _client() {
this->callback = callback;
this->domain = domain;
this->port = port;
}
int PubSubClient::connect(char *id) {
return connect(id,0,0,0,0);
}
int PubSubClient::connect(char *id, char* willTopic, uint8_t willQos, uint8_t willRetain, char* willMessage) {
if (!connected()) {
int result = 0;
if (domain != NULL) {
char c[40];
this->domain.toCharArray(c, 40);
result = _client.connect(c, this->port);
} else {
result = _client.connect(this->ip, this->port);
}
if (result) {
nextMsgId = 1;
uint8_t d[9] = {0x00,0x06,'M','Q','I','s','d','p',MQTTPROTOCOLVERSION};
uint8_t length = 0;
int j;
for (j = 0;j<9;j++) {
buffer[length++] = d[j];
}
if (willTopic) {
buffer[length++] = 0x06|(willQos<<3)|(willRetain<<5);
} else {
buffer[length++] = 0x02;
}
buffer[length++] = 0;
buffer[length++] = (KEEPALIVE/1000);
length = writeString(id,buffer,length);
if (willTopic) {
length = writeString(willTopic,buffer,length);
length = writeString(willMessage,buffer,length);
}
write(MQTTCONNECT,buffer,length);
lastOutActivity = millis();
lastInActivity = millis();
while (!_client.available()) {
long t= millis();
if (t-lastInActivity > KEEPALIVE) {
_client.stop();
return 0;
}
}
uint8_t len = readPacket();
if (len == 4 && buffer[3] == 0) {
lastInActivity = millis();
pingOutstanding = false;
return 1;
}
}
_client.stop();
}
return 0;
}
uint8_t PubSubClient::readByte() {
while(!_client.available()) {}
return _client.read();
}
uint8_t PubSubClient::readPacket() {
uint8_t len = 0;
buffer[len++] = readByte();
uint8_t multiplier = 1;
uint8_t length = 0;
uint8_t digit = 0;
do {
digit = readByte();
buffer[len++] = digit;
length += (digit & 127) * multiplier;
multiplier *= 128;
} while ((digit & 128) != 0);
for (int i = 0;i<length;i++)
{
if (len < MAX_PACKET_SIZE) {
buffer[len++] = readByte();
} else {
readByte();
len = 0; // This will cause the packet to be ignored.
}
}
return len;
}
int PubSubClient::loop() {
if (connected()) {
long t = millis();
if ((t - lastInActivity > KEEPALIVE) || (t - lastOutActivity > KEEPALIVE)) {
if (pingOutstanding) {
_client.stop();
return 0;
} else {
_client.write(MQTTPINGREQ);
_client.write((uint8_t)0);
lastOutActivity = t;
lastInActivity = t;
pingOutstanding = true;
}
}
if (_client.available()) {
uint8_t len = readPacket();
if (len > 0) {
lastInActivity = t;
uint8_t type = buffer[0]&0xF0;
if (type == MQTTPUBLISH) {
if (callback) {
uint8_t tl = (buffer[2]<<3)+buffer[3];
char topic[tl+1];
for (int i=0;i<tl;i++) {
topic[i] = buffer[4+i];
}
topic[tl] = 0;
// ignore msgID - only support QoS 0 subs
uint8_t *payload = buffer+4+tl;
callback(topic,payload,len-4-tl);
}
} else if (type == MQTTPINGREQ) {
_client.write(MQTTPINGRESP);
_client.write((uint8_t)0);
} else if (type == MQTTPINGRESP) {
pingOutstanding = false;
}
}
}
return 1;
}
return 0;
}
int PubSubClient::publish(char* topic, char* payload) {
return publish(topic,(uint8_t*)payload,strlen(payload));
}
int PubSubClient::publish(char* topic, uint8_t* payload, uint8_t plength) {
return publish(topic, payload, plength, 0);
}
int PubSubClient::publish(char* topic, uint8_t* payload, uint8_t plength, uint8_t retained) {
if (connected()) {
uint8_t length = writeString(topic,buffer,0);
int i;
for (i=0;i<plength;i++) {
buffer[length++] = payload[i];
}
uint8_t header = MQTTPUBLISH;
if (retained != 0) {
header |= 1;
}
write(header,buffer,length);
return 1;
}
return 0;
}
int PubSubClient::write(uint8_t header, uint8_t* buf, uint8_t length) {
_client.write(header);
_client.write(length);
_client.write(buf,length);
lastOutActivity = millis();
return 0;
}
void PubSubClient::subscribe(char* topic) {
if (connected()) {
uint8_t length = 2;
nextMsgId++;
buffer[0] = nextMsgId >> 8;
buffer[1] = nextMsgId - (buffer[0]<<8);
length = writeString(topic, buffer,length);
buffer[length++] = 0; // Only do QoS 0 subs
write(MQTTSUBSCRIBE,buffer,length);
}
}
void PubSubClient::disconnect() {
_client.write(MQTTDISCONNECT);
_client.write((uint8_t)0);
_client.stop();
lastInActivity = millis();
lastOutActivity = millis();
}
uint8_t PubSubClient::writeString(char* string, uint8_t* buf, uint8_t pos) {
char* idp = string;
uint8_t i = 0;
pos += 2;
while (*idp) {
buf[pos++] = *idp++;
i++;
}
buf[pos-i-2] = 0;
buf[pos-i-1] = i;
return pos;
}
int PubSubClient::connected() {
int rc = (int)_client.connected();
if (!rc) _client.stop();
return rc;
}